Piston



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R y MT am T E. o Y w H Y \V H. T. THOMAS PISTON Fiied May '7.

Nov. 6 E923.

Patented Nov. 5, i923.

hdi/@ttl PISTON.

Application inea May 7,

To all whom t may concern:

Be it known that I, Horace T. THoMAsfa citizen of the United States, residing at Lansing, county ot lngham, State of Michigan, have invented a certain new and useful Improvement in Pistons, and declarethe following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to pistons for engines and an object ot my improvements is to provide an improved piston tor internal combustion engines and one in which the piston pin shall not become loose. I secure this object in the device illustrated in the accompanying drawings, in which:

Figure l is a section of a piston embodying my invention.

lig. 2 is a detailed sectional view to an enlarged scale of a part ot the device of Fig. l illustrating its mode of o eration.

Fig. 3 is an inverted detailed plan view of a part of said apparatus.

a is the piston having the usual transverse aperture a2 for the reception of the piston pin. o is the piston pin in this case shown as tubular. b2 b2 are co-aXial apertures through the wall of the piston Z) toward one end thereof.

c is a pin having a screw threaded part o3 of larger diameter, and a part of smaller diameter extending from the part o3. c2 is a conical wall upon the pin c. Z13 is a concave conical portion of the wall at the lower part of the lower aperture b2.

c4 is the square head at the lower end ot the pin c. The pin c engages with its screw threaded portionrcs in an aperture through a portion a5 of the piston a.. The portion of said pin of smaller diameter passing through the holes b2 b2 and engaging in a portion at of the piston a above the piston pin b. The conical portion c2 ol the pin c engages against the conical wall b3 ot the lower aperture b2.

al is a coil spring surrounding the pin c towards its lower end. The lower spire of the spring ci is made rectangular as shown in Fig. 3 so as to tit over the square portion c4 of the pin o and the ends of the spring Z are extended to engage the wall of the piston pin upon opposite sides ot the pin o as 1921. Serial No. 467,733.

shown at Z2 d3. a3 is an annular ridge eX- tending around the inner wall of the piston a at its open lower end. rlhe end Z3 of the spring Z) engages above the annular ridge a3 to hold said spring in its position.

The relative size and location of the parts are such that in their normal position the square spire (Z4 ot the spring Z engages over the square end ct oit the pin c to lock said pin.

s is a socket wrench adapted to engage over the head o4 ot the pin c.

rFhe operation of the above described device is as follows:

To adjust the parts the socket wrench is engaged over the head o4 of the pin o as shown in Fig. 2 pressing the spire (Z4 to a position above the square head c4. The pin is then turned by the wrench until the conical portion b3 is pressed iirmly against the conical wall of the lower aperture Z22 of the pin o, thus clamping said pin in position and holding it iirmly. When the socket wrench s is removed the spire (Z4 of the spring l again engages over the square head o* and locks the pin in its position.

The engaging walls of the pin o and the aperture 52 are at an angle to the center line ot the piston pin so that the latter is firmly held against both longitudinal and transverse motion.

Claims:

l. rllhe combination of a piston, a piston pin, a screw threaded locking pin Jfor securing said piston pin, said locking pin having a squared head adjacent to the open end of said piston and adapted to be engaged by a Wrench. a spring adapted to automatically engage over the squared end 01"' said pin to hold the same 'from rotation, said spring being adapted to be pressed out of engagement with theJ squared end of said pin by the engaging wrench, said piston being provided with annular ridge around the open end7 said spring having a prong engaging over said ridge to prevent the spring from falln ing away from said pin.

2, The combination of a piston, a piston pin, a screw threaded locking pin for securing said pister] pin, said locking pin having a squared head and adapted to be engaged by a tool tor turning said pin, a spring adapted to automatically engage over the squared end of said pin to hold the same from rotation, said spring being adapted t0 be pressed out of engagement with the squared' end of said pin by the engaging` ay squared head and adapted to be engaged by a tool for turning said pin, a coil spring surrounding said locking pin and having a spire adapted to automatically engage over the squared 'end of' saidjpin to hold thesaiiie from rotation7 said vspring having a part thereof 'extending outwardand engaging the piston to prevent the rotation of said spring about its longitudinal axis. Y f

4'. Thecombination of a piston, a piston pin, a screw threaded'locking pin for securing said piston pin, said` locking pin having a squared'head and yadapted to beengaged by a tool for turning said pin, a coil spring surro'undlingsaid locking Vpin vand having a spire adapted to automatically engage over the squared end of said pin to hold the ysaine from rotation, the ends of the wire of which said spring i's made extending outward at an anfflein o osite directionsanden a incr n P h the piston wall to prevent the rotation of said 'spring about its longitudinal axis.

` 5. The combination of a piston, a lpiston pin, a screw threaded locking pin Jfor securing said piston ping, said locking pin having a squared head and adapted` to be engaged a tool for turning said pin, a coil spring Vfrom rotation, the ends of the wire ofwhich said spring is made extending outward at an Vangle. in opposite directions and engaging the piston Y,Wallto prevent the rotation oi' said spring about its longitudinal axis, said yspring being adapted to be pressed out of engagement with the squared end of said pin by the engaging wrench. y 1

6. The combination of a screw threaded said pin having a head, said spring having j a spire adapted to automaticallyengage said head to `preventthe relative rotation'offsaid pin and springe-nd means for pre-ventingthe rotation of Asaid spring with rsaid ping" 7. Thecombination of a screw threaded pin, a coil spring si'irroundiiilg said pin, said pin having a 'head and adapted to be engaged by a tool for turn-ing said vpin, said spring having a spire to automatically'eir gage saidhead to vprevent the rotation Aof said pin and means for preventing the roi tation of said spring with said head-,said spring being adapted to be pressedoiit 'ot engagement with the 'head of said pin by a tool engaging said pin to 'turn the saine.

ln testimony whereof I sign this specification.

HORACE T. ',TOMA'S;

lpin, a `coil spring surroundingrsaid pin,V 

